1. Field of the Invention
The present invention relates generally to a serial hub apparatus and more particularly, to a serial hub apparatus with at least one upstream port connector that can rotate in a plurality of directions with respect to a plurality of downstream port connectors.
2. Description of Related Art
In many applications, it is advantageous to interconnect a single serial computer port to multiple peripheral devices. A hub apparatus or hub provides a convenient central data connection point for attaching multiple peripheral devices to a computer. The hub relays data from the computer to all enabled devices connected to the data hub, and relays data from the enabled devices to the computer. This data relay can be performed without any data storage or significant delay. The hub can be connected to the computer via a single upstream connector. The hub can include a plurality of downstream ports for connecting the peripheral devices to the hub. Hubs utilize standardized connectors at the upstream and downstream ports to provide universal connectivity between peripheral devices and the computer, thus simplifying these connections. Hub assemblies utilizing serial data transfer protocols and the corresponding electrical or electro-optical connectors operate similarly. Exemplary protocols that can be used with hub assemblies include Universal Serial Bus (“USB”), IEEE 1394 (“Fire Wire”), PS2, and RS232.
Conventional USB hubs receive power for low power applications via a positive voltage conductor and a ground conductor from a source, such as the computer, through the upstream port. Conventional USB hubs can operate in the so-called “self-powered” mode when equipped with a connector for connecting with a transformer plugged into a typical AC outlet for providing DC power to the hub for high power applications.
The USB standard is a communication interface standard that enables data transmission/reception between a single USB host and a plurality of USB devices. USB standard compliant interfaces have been widely used as a communication interface that mainly defines a PC as the USB host and its peripheral devices as the USB devices to enable connection between the PC and the peripheral devices. The USB standard adopts a star-shaped logical bus topology in which a single USB host is connected with plural USB devices. The USB 2.0 standard defines three bus transport speeds: a low speed (“LS”) of 1.5 Mbits, a full speed (“FS”) of 12 Mbits, and a high speed (“HS”) of 480 Mbits. Most USB 2.0 hubs are backward compatible to the USB 1.1 standard that includes the LS and FS bus transport speeds.
Laptop computers often have only one or two type “A” USB ports available and they are commonly either located on the back or side of the laptop computer and little clearance is provided around the connectors for plugging in travel hubs or some of the larger USB devices that are integrated into the male USB connectors. If adequate clearance is available, to reduce the size of travel hubs and the cables the user needs to carry around while traveling, it would be preferable if the travel hub could plug directly into one of the laptop computer's USB ports similar to a USB flash memory drive. A number of such devices with one, two or even three USB ports molded into one rigid molded unit are currently available. Unfortunately, this solution is often not practical for the user to deploy in her situation, unless she makes use of an upstream extension cable, as the hub would block the user's access to other cables and devices plugged into the laptop. The use of an extension cable to get around the clearance problems thus defeats much of the benefits of using a single molded hub unit. Thus, many travel hub manufacturers settle for an alternative solution of having an integrated male type “A” USB connector and upstream cable permanently attached to the travel hub. When not in use, the upstream cable can be stored by folding it, coiling it into a bundle, or wrapping it around the circumference of the travel hub.
Some existing travel hubs attempt to solve the clearance problem by having a type “A” USB port that swivels in one direction but, this solution still does not always allow the hub to be positioned properly for adequate clearance to adjacent ports and connectors. An improved USB hub design would allow the user to easily position and connect her travel hub in a plurality of directions directly to the USB ports on her laptop computer, and would eliminate the use of an upstream cable and an extension cable when connecting a travel hub to one of her laptop computer's USB ports.
USB hubs can be configured in a variety of shapes and sizes with a varying number of ports, commonly ranging from 2 to 7 ports. Small portable hubs meant to be used with a laptop computer are commonly referred to as “travel hubs” with two to four available bus-powered ports. Often, when a laptop user docks her computer at home or work, she needs a USB hub that has more than the two to four bus-powered ports. That is, she is in need of self-powered ports, as described above. Until now, this meant that the laptop user needed to purchase two hubs, i.e., a travel hub and a larger conventional USB hub, to get additional ports with the DC powered port option.
Accordingly, there is a need for a small DC-powered hub that can be easily positioned in a plurality of directions, and folded and used in a compact shape, saving weight and space for the user.